<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
</html>
<script>
    var arr = {
        name: {value: '张三'},
        age: {value: '10'},
        sex: {value: '男'}
    }

    for (let i in arr) {
        console.log(i)
        delete arr[i]
        break;
    }
    console.log(arr)
</script>